Liquid petroleum gas valve for internal combustion engines



1960 P. s. NEUBAUER Q 2,

LIQUID PETROLEUM GAS VALVE FOR INTERNAL COMBUSTION ENGINES Filed Jan. 11, 1957 United States atent O LIQUID PETROLEUM GAS VALVE FOR INTERNAL COMBUSTION ENGINES Patrick s. Neubauer, Hibbing, Minn. Application January 11, 1957, Serial No. 633,736

1 Claim. (Cl. 48-180) engine for maximum running efficiency at a minimum operating cost. Further, when the engine is" shut off, the fuel supply must likewise be positively shut ofi to prevent loss thereof due to evaporation and leakage there of into the engine.

An important object of my invention is the provision of a carburetor of the above type having a throttle valve and a fuel metering valve operable with the throttle valve to meter the correct proportion of fuel to air for all operating speeds of the engine. To this end, I utilize a common control shaft for both valves so that both operate simultaneously to increase or decrease the amounts of fuel and air used at various engine speeds, and to completely shut oif the flow of fuel to the engine when the air supply thereto is reduced to a minimum or shut off completely.

Another object of my invention is the provision: of a carburetor as set forth having novel means for adjusti l the positions of the valves relative to each other to properly synchronize the same. i 1

Still another object of my invention is the provision of a carburetor having a fuel metering valve comprising a valve seat and a cooperating valve element mounted on the throttle valve shaft and having seating engagement with the valve seat, and yielding means urging the valve element toward seating engagement with the valve. seat, whereby tocause said seating engagement to be effected irrespectively of wear between the valve element and valve seat.

- Another object of my invention is the provision of a carburetor as set forth which is simple and inexpensive to produce, which is highlyeflicient in operation, and which is rugged in construction and durable in use.

The above, and still further highly important objects andadvantages of my invention will become. apparent from the following detailed specification, appended claims, and attached drawings. Referring to the drawings, which illustrate the invention, and in which'like reference characters indicate like parts throughout the several views:

,Fig- 1 is a view in bottom plan' of a carburetor built in accordance with my invention, some partsbeing broken away and some parts shown in section;

Fig. 2 is an enlarged longitudinal section taken substantially on the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary transverse section taken on the line 3--3 of Fig. 2, on a reduced scale;

5 "Fig.4 is a view corresponding to Fig. 3, but showing a different position of some of the parts; and

Fig. 5 is a view partly in end elevation and partly in section, taken on the line 5-5 of Fig. 2. n.

In the preferred embodiment of my invention illus- "ice trated, the numeral 1 indicates in its entirety an elongated body defining a gas passage 2 extending longitudinally therethrough and provided with an inlet end 3 and a diametrically reduced outlet end 4. Between the inlet and outlet ends 3 and 4 respectively, the passage 2 is formed to provide an annular shoulder 5 against which is seated a venturi tube 6. Adjacent the outlet end 4 of the gas passage 2, the body 1 is provided with a mounting flange 7 whereby the body is rigidly anchored to the intake manifold 8 of an internal combustion engine, not shown, by means of machine screws or the like 9. The external generally cylindrical wall of the venturi tube 6 is formed to provide a circumferentially extended channel 10 which cooperates with the adjacent wall portion of the passage 2 to define an annular compartment 11 which communicates wtih the interior of the venturi tube 6. by means of a plurality of fuel passages 12. As shown in Figs. 2 and 5, the fuel passages 12 extend generally radially inwardly and angularly toward the outlet end 4 in circumferentially spaced relation.

The body 1 is formed to provide a laterally extended boss 13 which defines a cylindrical metering valve cham ber 14, the axis of which is normal to the axis of the cylindrical passage 2, said chamber having a cylindrical wall 15 and a flat seat-forming inner end wall 16. Adjacent its outer end, the cylindrical wall 15 is screw threaded to receive a cooperating screw-threaded closure element or cap 16 which seals the outer end of the chamber 14 against escape of gaseous fuel from the chamber 14 to atmosphere. a

The axis of the valve chamber 14 is disposed between the venturi tube 6 and the inlet end of the gas passage 2; and the portion of thebody 1 between the valve chamber 14 and the adjacent portion of the gas passage 2 defines a port 17 which communicates at one end with the valve chamber 14 through the inner end wall 16 thereof in radially spaced relation to the axis of the valve chamber 14, and at its other end with the compartment 11 of the venturi tube 6. A fuel inlet fitting 18 is screw threaded into an inlet opening 19 of the body 1 for admitting fuel to the chamber 14 through the cylindrical wall surface 15 thereof, and a fuel conduit 20 leads outwardly from the fitting 18 to a source of fuel, not shown.

A control shaft 21 is journalled in the body 1 on the axis of the cylindrical valve chamber 14, the intermediate portion 22 of the control shaft, 21 extending transversely through the gas passage 2 ahead of the venturi tube 6 therein. A conventional disc-like throttle valve 23 is secured to the intermediate portion 22 of the control shaft 21 for common rotation therewith between a closed position, indicated by dotted lines in Fig. 4, and a fully opened position, as shown by dotted lines in Fig. 3. As

indicated in Fig. 2, the throttle valve 23 is of slightly less Width than the diameter of the adjacent portion of the gas passage 2 whereby to permit limited axial movement of the control shaft 21 with respect to the body 1. A control arm 24 is rigidly secured to the outer end 25 of the control shaft 21 and may be assumed to be connected to conventional control linkage whereby the operator is enabled to manipulate the throttle valve 23 to control operation of the engine.

The control shaft 21 is provided with a reduced diameter inner end. portion 26 which extends axially within the metering valve chamber 14, and which cooperates with the intermediate portion 22 to define a frusto-conical shoulder 27 adjacent the inner end wall 16 of the body 1, see Fig. 2. Mounted on the reduced diameter shaft portion 26 is a cylindrical metering valve element 28 having a diameter substantially that of the cylindrical surface '15 of the valve chamber 14, said diameter being only sufiiciently smaller to.- provide running clearance therebetween and said wall 15. The valve element 28 is provided with a central axial opening 29 therethrough for reception of the reduced diameter portion 26 of the control shaft 21, one end of the opening 29 being chamfered as indicated at 30 to engage the conical shoulder 27. The inner end 31 of the valve element 28 has seating engagement with the inner seat-forming end wall of the chamber 14. At its outer end, the shaft portion 26 is provided with an axially outwardly extending threaded stud 32 which has screw threaded thereon a retaining nut 33 that engages the outer end of the valve element 28 and forces the chamfered portion 30 against the conical shoulder 27 to frictionally lock the valve element 28 to the control shaft 21 for common rotation therewith. With this arrangement, the valve element 27 may be adjusted circumferentially with respect to the throttle valve 23 so that the throttle valve and valve element 28 may be properly synchronized for efficient operation as will hereinafter become apparent. A coil compression spring 34 is interposed between the outer end of the valve element 28 and the end cap 16', and yieldingly biases the valve element 28 into seating engagement of the inner end 31 thereof with the seat-forming inner end wall 16 of the chamber 14.

The valve element 28 is formed to provide a radially outwardly opening annular channel 35 that is in register with the inlet opening 19 and inlet fitting 18 in all positions of rotary movement of the valve element 28. Further, the valve element 28 is formed to provide an axially extended channel 36 which communicates at one end with the circumferentially extended channel 35 and at itsother end with the inner end wall 16 of the valve chamber 14, said axially extended channel 36 being adapted to be moved into registration with the port 17 during rotation of the valve element 28 in one direction, and to be moved out of registration with said port during rotation of the valve element 28 in the opposite direction. With reference particularly to Figs. 3 and 4, it will be seen that the channel 36 is so disposed with respect to the throttle valve 23, and is of such shape, that when the throttle valve is in its fully open position of Fig. 3, the entire area of the port 17 is open in full register with the channel 36; and, when the throttle valve 23 is moved toward its closed position of Fig. 4, the port 17 is gradually closed during corresponding rotary movement of the valve element 28. As shown, the cylindrical wall surface 15 of the chamber 14 cooperates with the channel-forming portions of the valve element 28 to define the channels or'passages 35 and 36, the channel 36 having a crosssectional shape resembling that of a bent wedge, whereby to utilize substantially the entire range of rotary movement necessary to fully open the throttle valve 23 from its fully closed position, to fully open the port 17 from its fully closed position, and vice versa. tional shape of the channel or passage 26 is such that the correct ratio of fuel to air in the outlet end of the outlet end portion 4 of the gas passage 2 is maintained in all positions of the throttle valve 23. It should be obvious that adjustmentof the metering valve element 28 with respect to the throttle 'valve 23 to provide a lean or rich mixture between the limits of rotary movements of the control shaft 21, may be had by loosening the nut 33 on the stud 32 and rotating the control shaft 21 with respect to the valve element 28 to the desired degree and in the desired direction. Thereafter, when the nut 33 is tightened against the outer end of the valve element 28, engagement of the chamfered portion 30 thereof with the conical shoulder 27, will maintain the valve element 28 lzolcked against rotation with respect to the control shaft Obviously, when the carburetor above described is used with an internal combustion engine for propelling a vehicle, the control shaft 21 is manipulated at frequent intervals to cause acceleration and deceleration of engine speeds. With this in mind, it will be appreciated that one or the other or both the inner endwall 16 and the inner end 31 of the valve element 28 will be subject to The cross secwear. With reference to Fig. 2, it will be seen that a slight clearance is provided between a portion of the throttle valve 23 and an adjacent cylindrical wall of the wall portion of the gas passage as'indicated at 37. When the aforementioned wear does occur, the compression spring 34 moves the valve element 28 and control shaft 21 in a direction to' maintain the end 31 of the valve element 28 in seating engagement with the inner end wall 16 of the chamber 14, the clearance indicated at 37 permitting' such axial movement of the control shaft 21. Although not shown, the throttle 'valve 23 may be secured to the intermediate portion 22 of the control shaft 21 for common rotation therewith but for limited axial movement with respect thereto to permit the above-mentioned axial movement of the control shaft 21. As such wear between the valve element 28 and the end wall .16 is very slight, the carburetor of the instant invention is capable .of use for an extreme length of time before the clearance indicated at 37 is reduced to a point where proper seating engagement between the valve element 28 and the chamber wall 16 is reduced to a point where leakage occurs through the port 17 when the valve element 28 is in its port-closed position of Fig. 4.

While I have shown and described a preferred embodiment of my carburetor construction, it will be understood that the same is capable of modification without departure from the spirit and scope of the invention as defined in the claim.

What I claim is:

In a carburetor comprising a body having a gas passage therethrough for communication with the firing chamber: of an internal combustion engine, said body defining a cylindrical chamber laterally spaced from said gas passage and having an axis normal to the axis of said gas passage, said body having a fuel inlet communicating with said chamber and adapted to be connected to a source of fuel, a control shaft extending transversely through said gas passage axially into said chamber through the inner end wall thereof, a throttle valve mounted on said shaft in said gas passage for common rotation with said shaft between open and closed positions to control flow of air through said gas passage, said body further defining a port extending through the inner end Wall of said chamber to said gas passage in radially spaced relation to the axis of said chamber and between said throttle valve and the outlet end of said gas passage, a generally cylindrical valve element in said chamber, and means for releasably locking the valve element on said control shaft for common rotation therewith, said valve element intermediate its ends having a radially outwardly opening circumferentially extended channel in register with said fuel inlet and having a radially outwardly opening axially extended channel communieating at one end with saidcircumferentially extended channel and extending to said inner wall of the chamber, said valve element and said throttle valve being so positioned relative to each other circumferentially of said control shaft'that said axially extended channel is moved circumferentially to gradually open said port upon rotation of said control shaft in a direction to open said throttle valve and in the opposite direction to gradually close said port during rotation of said control shaft in the opposite throttle valve closing direction, said valve element having seating engagement with said inner end wallof the chamber.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain 1912 

